1    package npw;
2    
3    import painter.SPainter;
4    import shapes.SCircle;
5    import javax.swing.*;
6    import java.awt.*;
7    import java.util.Random;
8    import java.util.Scanner;
9    
10   public class SimpleDots {
11   
12       private void paintTheImage(){
13           // Get the input information
14           int radius = getNumber("circle radius");
15           int dotradius = getNumber("dots diameter");
16           String color = getColor("Pick a color out of Red, Blue, or Green ");
17   
18           // Establish the painter
19           SPainter painter = new SPainter("Circle of dots", radius*2+50, radius*2+50);
20           painter.setBrushWidth(3);
21           SCircle circle = new SCircle(radius);
22           SCircle dot = new SCircle(dotradius);
23   
24           // Paint the squares
25           paintHirstSquares(painter, circle, dot, color);
26       }
27   
28       private String getColor(String s) {
29           String color = JOptionPane.showInputDialog(null,s+"?");
30           Scanner scanner = new Scanner(color);
31           return scanner.next();
32       }
33   
34       private void paintHirstSquares(SPainter painter, SCircle circle, SCircle dot, String color){
35           // Paint the circle of squares
36           double howFarToMove = 0;
37   
38           while (howFarToMove < circle.radius()) {
39               double chord = chordLength(howFarToMove, circle);
40               int dots = circleOnLineCount(chord, dot.diameter());
41               if (howFarToMove == 0) {
42                   paintRow(painter, dot, dots, color);
43               }
44               else {
45                   // Stay invariant with respect to painter position
46                   painter.mfd(howFarToMove);
47                   paintRow(painter, dot, dots, color );
48                   painter.mbk(howFarToMove * 2);
49                   paintRow(painter, dot, dots, color);
50                   painter.mfd(howFarToMove);
51               }
52               howFarToMove = howFarToMove + dot.diameter();
53           }
54       }
55   
56       // Assumes the painter is at the center of the row to paint, facing right.
57       private void paintRow(SPainter painter, SCircle dot, int squaresToPaint, String color){
58           // Turn right to start painting the row.
59           painter.tr();
60           // Move backward 1/2 of the length we're painting to get ready to paint the row.
61           double centerOffset = ( (squaresToPaint * dot.diameter()) / 2) - dot.diameter()/2;
62           painter.mbk(centerOffset);
63   
64           // Paint the row of squares.
65           int painted = 0;
66           while (painted < squaresToPaint){
67               paintOneSquare(painter, dot, color);
68               painter.mfd(dot.diameter());
69               painted = painted + 1;
70           }
71   
72           // Make the method invariant with respect to painter position.
73           painter.mbk(centerOffset + dot.diameter());
74           // Turn left to stay invariant with respect to direction.
75           painter.tl();
76       }
77   
78       private void paintOneSquare(SPainter painter,SCircle dot, String color){
79           if (color.equalsIgnoreCase("Blue")) {
80               painter.setColor(Color.BLUE);
81           } else if (color.equalsIgnoreCase("Red")) {
82               painter.setColor(Color.RED);
83           } else if (color.equalsIgnoreCase("Green")) {
84               painter.setColor(Color.GREEN);
85           } else {
86               painter.setColor(Color.BLACK);
87           }
88           dot.s2();
89           painter.paint(dot);
90           dot.x2();
91       }
92   
93       private static int circleOnLineCount(double lineLength, double sideLength){
94           int dots = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1);
95           return dots;
96       }
97   
98       private double chordLength(double yOffset, SCircle circle){
99           double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2));
100          double chordLength = xLength * 2;
101          return chordLength;
102      }
103  
104      private static int getNumber(String prompt) {
105          String nss = JOptionPane.showInputDialog(null,prompt+"?");
106          Scanner scanner = new Scanner(nss);
107          return scanner.nextInt();
108      }
109  
110      private static Color randomColor() {
111          Random rgen = new Random();
112          int r = rgen.nextInt(256);
113          int g = rgen.nextInt(256);
114          int b = rgen.nextInt(256);
115          return new Color(r,g,b);
116      }
117  
118      public SimpleDots() {
119          paintTheImage();
120      }
121  
122      public static void main(String[] args) {
123          SwingUtilities.invokeLater(new Runnable() {
124              public void run() {
125                  new SimpleDots();
126              }
127          });
128      }
129  }
130